Electrical stimulation and recordation of neural tissue may be performed by implanting into the tissue a device that includes an electrical lead having one or more electrodes. Typically, the lead is coupled to a signal generator that delivers electrical energy through the electrodes to the neural tissue, thereby stimulating an increase, decrease, or block of neuronal activity. The electrical response of the neural tissue may be measured and recorded.
Optical techniques may also be used for stimulating, monitoring, inhibiting, and/or modulating neural activity. Photo-stimulation, for example, may include various modes of interaction between light and the target neurons, including a variety of photo-physical and photo-biochemical effects, with various intrinsic components or exogenous sensitizers.
Devices for such purposes have received increasing attention from researchers and clinicians, especially as biomaterials and the technology of microscale probes and electronics have improved. Existing devices, however, are incapable of performing a desired combination of optical and electrical interrogation and/or recordation. Further, implantation of such devices may cause tissue damage and scar tissue buildup, which existing devices and methods are incapable of adequately detecting and monitoring.
Accordingly, there is a need for an improved, small-scale neurological device for electrically and/or optically stimulating and recording neural activity.